The Effect of Aprotinin on Platelet Function, Blood Coagulation and Blood Lactate Level in Total Hip Replacement - A Double Blind Clinical Trial

Abstract

Patients undergoing alloarthroplastic hip replacement are frequently endangered by pulmonary, cardiovascular and thrombotic complications occuring during and after surgery. This is due to an activation of both the humoral and cellular blood coagulation by the intravasation of thromboplastic material. In this context, the reactivity of platelets plays a specific role; e.g. Schlag et al. have shown by electron microscopical studies of lung biopsies from shock patients that besides neutrophil granulocytes, platelets are also trapped in the capillary and precapillary system¹⁹. According to Bergentz et al., reversible platelet aggregates in the pulmonary circulation are the first morphological substrate of a disturbance of microcirculation in shock. The resulting pulmonary failure is not only due to a mechanical obstruction of the blood vessels in the lung, but rather to the release reaction of aggregated platelets. These released substances are mainly ADP, serotonin, histamine, catecholamines, prostaglandins, hydrolases, and the platelet factors 3 and 4. Thus vasoconstriction, an increased permeability, and procoagulant activity are initiated^{1, 2}. Even during an operation, as for example, total hip replacement and other major bone surgery, an instant stimulation of the platelet function has been observed in patients¹¹. Modig et al. have reported that major bone surgery can lead to pulmonary complications which are very similar to those of a “shock lung”. An acute pulmonary dysfunction with an increased vascular resistance in the lung, a constriction of the bronchioli and a decrease of PaO₂, have been seen in patients with total hip replacement¹⁵.